CN104303349B

CN104303349B - Composite graphite material and its manufacture method, anode material for lithium-ion secondary battery, lithium ion secondary battery cathode and lithium rechargeable battery

Info

Publication number: CN104303349B
Application number: CN201380025464.1A
Authority: CN
Inventors: 美野裕香里; 江口邦彦
Original assignee: JFE Chemical Corp
Current assignee: JFE Chemical Corp
Priority date: 2012-05-14
Filing date: 2013-04-24
Publication date: 2017-06-09
Anticipated expiration: 2033-04-24
Also published as: TW201402457A; KR20150001810A; TWI469921B; KR101661050B1; JP2013258130A; JP6087648B2; WO2013171985A1; CN104303349A

Abstract

The present invention provides a kind of composite graphite material and its manufacture method, anode material for lithium-ion secondary battery and lithium rechargeable battery using the composite graphite material.The composite graphite material is made up of following component：Adhesive A, flaky graphite material B and the spheroidizing or the graphite material C of approximate sphericity formed by carbon material and/or low-crystalline graphite material, it is characterized in that, at least a portion of the flaky graphite material B is attached on the graphite material C by described adhesive A overshooting shapes, the content of described adhesive A is 0.1~20 mass %, the content of the flaky graphite material B is in more than 0.05 mass %, less than 30 mass %, the content of the graphite material C is 99.8~50 mass %, and the composite graphite material does not have the plane of fracture.

Description

Composite graphite material and its manufacture method, anode material for lithium-ion secondary battery, lithium Ion secondary battery negative pole and lithium rechargeable battery

Technical field

The present invention relates to composite graphite material, the anode material for lithium-ion secondary battery using it and use its lithium Ion secondary battery, more particularly to fast charging and discharging characteristic and the excellent anode material for lithium-ion secondary battery of cycle characteristics and Lithium rechargeable battery.

Background technology

In recent years, the miniaturization with electronic equipment or high performance, to the expectation of battery high energy metric density increasingly It is high.Especially compared with other secondary cells, lithium rechargeable battery being capable of Towards Higher Voltage, raising energy density (owing because of it To their high energy density and high voltage) and attract attention.Lithium rechargeable battery is with negative Pole, positive pole and nonaqueous electrolyte are main inscape.Produced by nonaqueous electrolyte (nonaqueous electrolyte) Lithium ion is moved in discharge process and charging process between negative pole and positive pole, forms secondary cell.Generally, carbon material is used Make the negative material of above-mentioned lithium rechargeable battery.Used as this carbon material, charge-discharge characteristic is excellent, show high discharge capacity Graphite (patent document 1 etc.) with current potential flatness (flatness of the electric potential) is considered as special With prospect.

Can be the graphite particles such as native graphite, Delanium as the graphite (graphite particle) as negative material, Can be the mesophase pitch with tar, pitch as raw material, mesophasespherule are heat-treated obtained by bulk mesophase (bulk mesophase) graphite particle, mesophasespherule graphite particle, by granular, fibrous mesophase pitch oxidation not Meso-phase graphite particle, meso-phase graphite fiber obtained by being heat-treated again after fusing (oxidation treament), use Composite graphite particle etc. obtained by being heat-treated again after the coated natural graphites such as tar, pitch, Delanium.

Additionally, for fast charging and discharging characteristic, the purpose of cycle characteristics is improved, studying and adding in above-mentioned graphite particle Plus conductive auxiliary agent is combined.It for example can be complex carbon material that the graphite material that is formed by spherical particle and carbon fiber are constituted (patent document 2), mixing graphite granule and asphalt, flaky graphite and granulate, the negative material (patent of Composite Document 3), in graphite granule surface attachment flaky graphite and negative material (patent document 4) obtained by crushing.

Above-mentioned existing anode material for lithium-ion secondary battery will not fill the discharge capacity of lithium rechargeable battery, initial stage Discharging efficiency is deteriorated significantly, can to a certain extent improve fast charging and discharging characteristic, cycle characteristics, but also has following problems.

Simply mixing negative pole material obtained from gas-phase growth of carbon fibre in graphite particle described in patent document 2 Material is the graphite in the case of negative material obtained from composite fibre shape graphite in globular graphite or flaky graphite The discharge capacity of the gas-phase growth of carbon fibre of change itself, initial charge/discharge efficiency are also lower than the meso-phase graphite of parent, thus deposit In the low problem of the discharge capacity as negative material, initial charge/discharge efficiency.And, in gas-phase growth of carbon fibre and parent Between phase graphite touch opportunity it is few, be helpless to electric conductivity raising situation it is many.As a result, fast charging and discharging characteristic, cycle characteristics Improved effect it is insufficient.Additionally, gas-phase growth of carbon fibre is more expensive, due to needing largely to carry out with as 3~20 mass % Mixing, thus also there is a problem of cost increase.Additionally, negative material, solvent, adhesive are mixed by use during manufacture negative pole Close, modulation cathode agent paste, the method being again applied to the paste on collector, but due to the combined amount of gas-phase growth of carbon fibre It is many, thus also there are problems that the viscosity of cathode agent paste.

Born mixing graphite granule and asphalt, flaky graphite described in patent document 3, obtained by granulation In the case of the material of pole, the amount of the flaky graphite of incorporation is big, is 40 mass %, thus it is interparticle with adjoining to there is formation The problem that remainder beyond contact point is orientated in electrode, fast charging and discharging and cycle characteristics are deteriorated.Additionally, also existing negative Pole mixture pastes viscosity destabilization, the problem of electrode insufficient compression.

In the situation for having the negative material of flaky graphite in graphite granule surface attachment described in patent document 4 Under, it is desirable to have pulverizing process, thus there is reactivity face and can expose and electrolyte overreaction, when causing initial stage discharge and recharge The problem of heating, expansion that gas when inefficiency, reaction causes etc.Additionally, also existing due to crushing, it is attached to The problem that the flaky graphite of graphite surface comes off, cycle characteristics improved effect is insufficient.Patent document：

Patent document 1：Japanese Patent Publication 62-23433 publications

Patent document 2：Japanese Unexamined Patent Publication 4-237971 publications

Patent document 3：Japanese Unexamined Patent Publication 2001-148241 publications

Patent document 4：Japanese Unexamined Patent Publication 2004-127723 publications

The content of the invention

The present invention makes in view of the foregoing, its object is to provide following negative material as lithium ion secondary Negative electrode battery material：High discharge capacity (discharge capacity) and initial charge/discharge efficiency (charge- high can be obtained Discharge efficiency), and then excellent fast charging and discharging characteristic and excellent cycle characteristics can be obtained, additionally, from Industrial point of view considers, additionally it is possible to easy and inexpensively manufactured.Additionally, the present invention also aims to provide using this negative The lithium rechargeable battery that pole material is formed.

Composite graphite material of the invention is made up of following component：Formed by carbon material and/or low-crystalline graphite material Adhesive A,

Flaky graphite material B, and

The graphite material C of spheroidizing or approximate sphericity, it is characterised in that

At least a portion of the flaky graphite material B is attached to the graphite by described adhesive A overshooting shapes In material C,

Relative to described adhesive A, the flaky graphite material B, the graphite material C total amount,

The content of described adhesive A is 0.1~20 mass %,

The content of the flaky graphite material B in more than 0.05 mass %, less than 30 mass %,

The content of the graphite material C is 99.8~50 mass %,

And the composite graphite material is without rupture (fracture) face.

In composite graphite material of the invention, can make to form the flaky graphite material B of composite graphite material and/or stone Ink material C is without rupture (fracture) face.

Additionally, in composite graphite material of the invention, the average grain diameter of preferably described flaky graphite material B is described The average grain diameter of graphite material C more than 1%, less than 80%, the length-width ratio of the flaky graphite material B is more than 2.9.

Composite graphite material of the invention is preferably by the flaky graphite material B and/or graphite material C The manufacture method without pulverizing process is manufactured after the mixed processing operation processed with described adhesive A.

Composite graphite material of the invention can be used in lithium ion secondary battery cathode.

The present invention is to use any of the above-described kind of anode material for lithium-ion secondary battery of composite graphite material.

The present invention is the lithium rechargeable battery for using above-mentioned anode material for lithium-ion secondary battery.

The present invention is the manufacture method of composite graphite material, with following operation：Will be by carbon material and/or low-crystalline stone Ink material formed adhesive A or described adhesive A precursor,

Flaky graphite material B and

The graphite material C mixing of spheroidizing or approximate sphericity, the mixed processes for obtaining mixture,

Mixture to being obtained in the mixed processes is heat-treated at 700~3300 DEG C, is obtained of the invention The heat treatment step of composite graphite material.

Flaky graphite material B and

Mixture to being obtained in the mixed processes implements the mechanochemistry treatment process of mechanochemistry treatment,

Mechanochemistry processed material to being obtained in the mechanochemistry treatment process carries out hot place at 700~3300 DEG C Manage, obtain the heat treatment step of composite graphite material of the invention.

Composite graphite material of the invention (compound graphite material) is used as the lithium ion secondary electricity that negative material is formed Pond has rapid charge rate high, repid discharge rate, and initial charge/discharge efficiency and cycle characteristics are also excellent, and discharge capacity is also excellent Different, moreover, the manufacturing cost of composite graphite material itself is also low.Therefore, formed using composite graphite material of the invention Lithium rechargeable battery meet requirement in recent years to the high-energy-density of battery, to the miniaturization of equipment carried and height Performance-based is effective.

Brief description of the drawings

Fig. 1 is a sectional view for example for schematically showing composite graphite material of the invention.

Fig. 2 is shown in embodiment the schematic cross-sectional of the structure that battery is evaluated for the coin shape of charge and discharge electric test Figure.

Fig. 3 is the composite graphite material of gained in the embodiment of the present application 1 shot with SEM (SEM) The photo of outward appearance.

Fig. 4 is the composite graphite material of gained in the embodiment of the present application 7 shot with SEM (SEM) The photo of outward appearance.

Specific embodiment

More specific description is carried out to the present invention below.

Lithium rechargeable battery is generally main battery inscape with nonaqueous electrolyte, negative pole and positive pole, and these will Element is enclosed in such as battery can.Negative pole and positive pole play lithium ion carrier respectively.In battery structure, during charging, lithium Ion is embedded into negative pole, and during electric discharge, lithium ion is from negative pole deintercalation.

Secondary cell of the invention in addition to using composite graphite material of the invention as negative material, without special limit System, other battery inscapes such as nonaqueous electrolyte, positive pole, dividing plate according to general secondary cell key element.

(adhesive A)

The adhesive A used in composite graphite material of the invention is made up of carbon material and/or low-crystalline graphite material. That is, adhesive A contains carbon material and/or low-crystalline graphite material.

The adhesive A formed by carbon material and/or low-crystalline graphite material is used to bond graphite material C and flakey stone Ink material B.The adhesive A is preferably conductive.

Here, carbon material and/or low-crystalline graphite material be meant that, relative in composite graphite material of the invention The graphite material C for using, adhesive A is the relatively low material of crystallinity.

Specifically, refer to adhesive A X-ray diffraction in average lattice face be spaced d002 (unit nm) than graphite material Expect the big situations of the d002 of C.

From the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtain more excellent fast From the point of view of fast charge-discharge characteristic and excellent cycle characteristics, the preferred scope of the d002 of adhesive A for 0.3358~ 0.3500nm, more preferably 0.3358~0.3400nm.During less than 0.3358, because crystallinity is too high, adhesive A is had sometimes Expose reactivity face, and electrolyte overreaction, inefficiency when causing initial stage discharge and recharge, by reacting when gas draw The problem of the heating, the expansion that rise etc.During more than 0.3500, the initial charge/discharge efficiency of adhesive A itself lowly can manifest, The initial charge/discharge efficiency for sometimes resulting in the composite graphite material of final gained is low.

By using the adhesive A being made up of carbon material and/or low-crystalline graphite material, initial charge/discharge efficiency is carried It is high.

The content of above-mentioned adhesive A relative to adhesive A, flaky graphite material B, above-mentioned graphite material C total amount, preferably It is 0.1~20 mass %, from the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtains more From the point of view of excellent fast charging and discharging characteristic and excellent cycle characteristics, preferably 0.2~15 mass %, more preferably 0.5~5 mass %.This is because, when adhesive A is less than 0.1 mass %, the bonding with adjacent particle is not enough, more than 20 Under the amount of quality %, then flaky graphite material B can be hindered to form contact with adjacent particle.

As the precursor of the adhesive A for using in the present invention, as long as carbon material and/or low-crystalline graphite material can be obtained Material, can be any material, but preferably tar asphalt class and/or heat-curing resin.Specifically, can be petroleum or coal Oil, the drip of tar heavy oil, naphtalene oil, carbolineum, coal tar in tar asphalt class, such as coal tar, tar light oil, the tar of charcoal system Green grass or young crops, coal tar, mesophase pitch, oxygen crosslinking asphalt, heavy oil, heat-curing resin, such as phenolic resin, furane resins. Especially tar asphalt class because can reduce gained composite graphite material (negative material) discharge capacity decline and it is preferred that.It is logical Cross and these precursors are heat-treated at 700~3300 DEG C, above-mentioned carbon material and/or low-crystalline graphite material can be obtained Material.The heat treatment can be carried out periodically several times, can also be carried out in the presence of a catalyst.Additionally, can be in oxidisability or non- Carried out under any one in oxidative environment.

Adhesive A individually or can combine two or more and use.

(flaky graphite material B)

The flaky graphite material B used in composite graphite material of the invention is the graphite for being shaped as flakey.Scale Shape graphite material B for example can be any shape in flakey, tabular, sheet, can be Delanium or native graphite, can Being the state of multiple stackings.Wherein, preferably with the scattered state of single particle.It can be the shape of the bent intermediate of scale shape The state that state, particle end are rounded.

Flaky graphite material B be the bent intermediate in scale shape into the case of such as L fonts, can be formed as follows State：1 face for forming L fonts contacts with graphite material C, forms another 1 face of L fonts from the protrusion of surface of graphite material C Shape is protruded.

As long as flaky graphite B is in the state of the bent halfway disperseed with single particle and in scale, just can be with adjoining Particle forms more contacts, so as to obtain more excellent cycle characteristics.The volume of the flaky graphite material B of this state Greatly, Tap density is low.Specifically, the Tap density of flaky graphite material B is preferably 0.1~0.9g/cm³.In addition, Tap is close Degree refer to powder is fitted into regulation container in rap (vibration) 1000 times, make it more substantial in the state of measure accumulation it is close Degree.

From the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtain more excellent fast From the point of view of fast charge-discharge characteristic and excellent cycle characteristics, the preferred scope of the d002 of above-mentioned flaky graphite material B exists Below 0.3380nm.Further preferably in below 0.3360nm.

From the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtain more excellent fast From the point of view of fast charge-discharge characteristic and excellent cycle characteristics, the average grain diameter of flaky graphite material B is above-mentioned graphite material Expect the 1~85% of the average grain diameter of C, preferably more than 1%, less than 80%, particularly preferably more than 15%, be less than 50%.When the average grain diameter of flaky graphite material B is less than the 1% of graphite material C, the initial stage caused by increasing except specific surface area Beyond efficiency for charge-discharge reduction, flaky graphite material B and adjacent graphite material C and/or squama on graphite material C are attached to The contact of flake graphite material B forms insufficient, and the improved effect of fast charging and discharging and cycle characteristics is small.Flaky graphite material When the average grain diameter of B exceedes the 85% of graphite material C, number of contacts is reduced, and electric conductivity improves effect reduction.In addition, average grain diameter System is distributed with laser diffraction granularity to measure.

From the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtain more excellent fast From the point of view of fast charge-discharge characteristic and excellent cycle characteristics, the mean aspect ratio of flaky graphite material B preferably 2.9 with On.Length-width ratio is big, the material of thickness of thin, when being made the composite graphite particle of final gained, more can be with other negative electrode actives Material equably contacts, fully improve the electric conductivity of negative pole, improves quick charge, cycle characteristics.Mean aspect ratio is less than When 2.9, when being made the composite graphite particle of final gained, active material layer is set to be high density, it is necessary to high pressure, sometimes There is Copper Foil deformation, stretching, the problem of rupture as collector.Additionally, length-width ratio refers to 1 of flaky graphite material B The major axis of particle is long the ratio between long relative to short axle.Here, axial length long refers to the most major diameter of measure object particle, short axle is long refer to The vertical minor axis of the major axis of measure object particle.Additionally, mean aspect ratio is to observe 100 flakeys with SEM Graphite material B and the simple average value of the length-width ratio of each particle that measures.Here, multiplying power when being observed with SEM It is the multiplying power of the shape for being able to confirm that measure object particle.

From the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtain more excellent fast From the point of view of fast charge-discharge characteristic and excellent cycle characteristics, relative to adhesive A, flaky graphite material B, above-mentioned graphite The total amount of material C, the amount of flaky graphite material B is in more than 0.05 mass %, less than 30 mass %, preferably 0.5~12 matter Amount %, especially preferably more than 0.5 mass %, less than 10 mass %.When ratio is very few, it is impossible to form contact with adjacent particle, The raising effect reduction of fast charging and discharging efficiency and cycle characteristics.On the other hand, when being present in excess, because specific surface area increases, Initial charge/discharge efficiency reduction.

Flaky graphite material B can individually using or two or more be applied in combination.

Furthermore, it is possible to make by flaky graphite material B and different from the small graphite particle combination of flaky graphite material B With.The small graphite particle can be any shape such as spherical, approximate sphericity, flakey, tabular, sheet, can be artificial stone Ink or native graphite.Its average grain diameter is preferably smaller than the average grain diameter of flaky graphite material B.

(graphite material C)

Graphite material C's is shaped as spherical or approximate sphericity, material for graphite, without specifically limited.

As graphite material C, for example, can be by processing material obtained in flaky graphite, by flat, flakey Native graphite bend, fold, being allowed to material obtained by approximate sphericity, composite graphite material described later.Graphite material C's In particle, preferably multiple graphite random arrangements, and preferably the native graphite or Delanium of flakey for be a granulated into concentric circles, The structure of cabbage shape.This is because, as described above, composite graphite material (negative material) will not be arranged in one direction And electrolyte is readily permeable to inside, fast charging and discharging efficiency and cycle characteristics raising.

Part or all of the graphite of composition graphite material C is formed by graphite type material, to its species without special Limitation, can be native graphite, the Delanium that tar, pitch class are finally heat-treated and are formed more than 1500 DEG C. Specifically, can enumerate and the whole of (graphitization) is heat-treated to the mesophase pitch with tar, pitch class as raw material Body meso-phase graphite particle, people obtained by (graphitization) is heat-treated to former Jiao, green coke, pitch coke, needle coke, petroleum coke etc. Make graphite.

To the manufacture of graphite material C without specifically limited.For example machine can be applied by the native graphite to flat, flakey Tool external force and manufacture.Specifically, its bending, spheroidizing can be made by applying high shear force or by implementing rolling operation, or Concentric circles are a granulated into, spheroidizing is carried out.Also adhesive can be added after spheroidizing before processing to promote granulation.As can enter The device of row spheroidizing treatment, can be " counter-jet mill " " ACM Pulverizer " (thin river close Krona company manufacture), Pulverizers such as " Current Jet " (manufactures of Qing industrial groups), " SARARA " (manufacture of Kawasaki Heavy Industries company), " GRANUREX " (manufacture of Freund industry companies), New Gramachine (manufacture of Seishin Enterprise companies), " Agromaster " Comminutors such as (the thin close Krona company manufactures in river), pressure kneader, double roll mill, " Mechano-micro system " (how Manufactured by good machinery production), extruder, ball mill, planetary ball mill, " Mechano-fusion system " (close gram of thin river Lang companies manufacture), " Nobilta " (thin river close Krona company manufacture), " Hybridization " (nara machinery makes made Make), shearing processing unit (plant) of the compression such as rotating ball mill, etc..

From the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtain more excellent fast From the point of view of fast charge-discharge characteristic and excellent cycle characteristics, the d002 of graphite material C is preferably 0.3350~0.3380nm, More preferably 0.3350~0.3370nm.

The preferred average grain diameter of above-mentioned graphite material C is 4~50 μm, especially preferably 10~25 μm.Average grain diameter is too small When, reference area increase, initial charge/discharge efficiency reduction.On the other hand, when excessive, electrode is uneven, orientation increase, causes fast Fast discharge and recharge, cycle characteristics reduction.

From the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtain more excellent fast From the point of view of fast charge-discharge characteristic and excellent cycle characteristics, relative to adhesive A, flaky graphite material B, graphite material The total amount of C, the content of graphite material C is 50~99.8 mass %, especially preferably below 85 mass %~99 mass %.Graphite When the amount of material C is very few, discharge capacity, initial charge/discharge efficiency reduction.On the other hand, when being present in excess, it may appear that with adjoining The contact of particle forms bad, fast charging and discharging, cycle characteristics reduction.Graphite material C can be used individually or two or more group Conjunction is used.

(composite graphite material)

Composite graphite material of the invention is by adhesive A, flaky graphite material B, spherical or approximate sphericity graphite material Material C constitutes (composite graphite material of the invention at least contains adhesive A, flaky graphite material B and graphite material C), wherein, Adhesive A is formed by carbon material and/or low-crystalline graphite material, and at least a portion of flaky graphite material B is by bonding Agent A overshooting shapes ground adheres to the graphite material C.In the overshooting shape part of flaky graphite material B, flaky graphite material B Contact is formed with other graphite particles, thus, it is possible to improve electric conductivity.Other graphite particles also can be with flaky graphite material B's Surface forms contact.

Additionally, being combined by making flaky graphite material B and spherical or approximate sphericity graphite material C, it is prevented from Orientation in electrode, maintains logical fluidity.As long as adhesive A is attached to flaky graphite material B and the graphite material C at least In a part.

Composite graphite material of the invention is characterised by without the plane of fracture.

The plane of fracture refers to that flaky graphite material B and/or graphite material C for example make its shape be subject to break because pulverized Face that is bad, exposing inside.Here, adhesive A and/or flaky graphite material B without being adhered to the plane of fracture of graphite material C On.Adhesive A and/or graphite material C without being adhered on the plane of fracture of flaky graphite material B.In composite graphite material tool In the case of having the plane of fracture, the reactive site of the inside of flaky graphite material B and/or graphite material C exposes, Ke Nengcheng The reason for being deteriorated for initial charge/discharge efficiency and/or cycle characteristics.

For composite graphite material of the invention, the flaky graphite material used during the composite graphite material is manufactured B and graphite material C can form composite graphite material in the case where its shape is maintained substantially.

When composite graphite material of the invention is manufactured, bonded by flaky graphite material B and/or graphite material C After precursor processing (mixing) of agent A or adhesive A, pulverizing process is not set, thus enable that composite graphite material of the invention not With the plane of fracture.

Additionally, by the surface as setting adhesive A after flaky graphite material B and/or graphite material C is crushed The operation that inorganic agent is surface-treated, can make composite graphite material of the invention not have the plane of fracture.

From the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtain more excellent fast From the point of view of fast charge-discharge characteristic and excellent cycle characteristics, composite graphite material of the invention is not further preferably attached The flaky graphite material B on graphite material C.

As the non-cohesive flaky graphite material B on graphite material C, for example, can be：Make flaky graphite material The flaky graphite material B that material B is separately added after being attached on graphite material C；Stone is attached to flaky graphite material B is made The non-cohesive flaky graphite material B remained on graphite material C after operation on ink material C.

Further contain the non-cohesive flaky graphite material B on graphite material C in composite graphite material of the invention In the case of, the amount of flaky graphite material B includes the amount of the non-cohesive flaky graphite material B on graphite material C.

In addition, composite graphite material (negative material) of the invention be containing graphite material C, flaky graphite material B and The complex of adhesive A, within the scope without prejudice to the object of the present invention, can add the carbon materials such as noncrystalline hard carbon, organic matter, Metal, metallic compound etc..

Composite graphite material of the invention is illustrated underneath with the accompanying drawing for attaching.Fig. 1 is to schematically show this One sectional view of example of the composite graphite material of invention.In Fig. 1, composite graphite material 10 is by by carbon material and/or low The graphite of adhesive A 12, flaky graphite material B14~18 and spheroidizing or approximate sphericity that crystalline graphite material is formed Material C 19 is constituted, and is attached on graphite material C19 at least a portion overshooting shape of flaky graphite material B14~18.And And, at least a portion of flaky graphite B14~18 is attached on graphite material C19 by adhesive A 12.

Here, it is attached on graphite material C refers to at least a portion overshooting shape of flaky graphite material B, by squama The part in the face that flake graphite material B has connects with the surface of graphite material C or has by flaky graphite material B The part of end connect with the surface of graphite material C, the end of flaky graphite material B is (except the surface with graphite material C Outside the part for connecting) with the surface of graphite material C from state.Now, flaky graphite material B and/or graphite material C A part or entirety can be coated by adhesive A.In Fig. 1, flaky graphite material B15,16 end a part (in figure not Show) with the surface of graphite material C19 from overshooting shape ground is attached thereto.The end of flaky graphite material B14,17,18 Two side's (not shown)s and graphite material C19 surface from overshooting shape ground is attached thereto.

Additionally, at least a portion of flaky graphite material B is attached on graphite material C by adhesive A referring to, scale The part in the face that shape graphite material B has is connected with the surface of graphite material C by adhesive A 12, or flaky graphite One side of the end that material B has is connected with the surface of graphite material C by adhesive A 12.That is, refer in flaky graphite material There is adhesive A between the parts in face that have of material B or the surface of a part for end and graphite material C.Flaky graphite In the face that material B has, in addition to the part connected with the surface of graphite material C by adhesive A, can have and graphite material Expect the part (being also same for the end that flaky graphite material B has) of the surface directly contact of C.Now, scale Part or all of shape graphite material B and/or graphite material C can be coated by adhesive A.In Fig. 1, in flaky graphite material There is adhesive A 12 between the material part in face that has of B14,17,18 and the surface of graphite material C19.Additionally, flakey stone One side's (not shown) of the end of ink material B15 is embedded in graphite material C19 and overshooting shape ground is attached thereto, in squama Exist between part (not shown) and the surface of graphite material C19 on flake graphite material B15 embedded part viscous Mixture A12.

(manufacture of composite graphite material (negative material))

For composite graphite material of the invention (negative material), as long as can manufacture (such as to flaky graphite Processing) spherical or approximate sphericity graphite material C and flaky graphite material B is by by carbon material and/or low crystallization Property the adhesive A that is formed of graphite material or adhesive A precursor and the method for complex adhered to, can carry out by any method Manufacture.Flaky graphite material B and graphite material C can be enumerated composite graphite material is formed in the case where its shape is maintained substantially The method of a material example preferably.

Representational manufacture method is described below.Additionally, can be using the method for following (1)~(4) as in mixed processes Each composition order of addition concrete mode example.

(1) precursor for making adhesive A or adhesive A is attached on flaky graphite material B, again that gains are further attached The method on graphite material C.

(2) precursor of adhesive A or adhesive A is made to be attached on graphite material C, further bury squama on gains again The method of flake graphite material B.

(3) method for adhering to the precursor of graphite material C, flaky graphite material B and adhesive A or adhesive A simultaneously.

(4) flaky graphite material B is attached on graphite material C in advance, the adhesive bonding agent A or viscous on gains again The method of the precursor of mixture A.In (4), at least a portion of flaky graphite material B also can be by adhesive A overshooting shape Be attached on graphite material C.

Method as composite graphite material of the invention is manufactured, can enumerate in addition to mixed processes, as needed for example With mechanochemistry treatment process, the method for heat treatment step.

As the order of operation, for example, can be：The manufacture method (I) of mixed processes, the order of heat treatment step；Mixing Operation, mechanochemistry operation, the manufacture method (II) of the order of heat treatment step；Mechanochemistry treatment process, mixed processes, heat The manufacture method (III) of the order for the treatment of process.Wherein, manufacture method (I), manufacture method (II) can be enumerated as preferred side Formula.In addition, mixing and mechanochemistry treatment can also be carried out simultaneously.

One of additionally, preferably, can enumerate：Using as the flaky graphite material B of raw material and/or (mixed processes that mixed processing operation is recorded afterwards therewith are in reality for the mixed processing operation that graphite material C is processed with adhesive A It is identical in matter) or using as the adhesive A or described formed by graphite material and/or low-crystalline graphite material of raw material The graphite material C of the precursor, flaky graphite material B and spheroidizing or approximate sphericity of adhesive A mixes, obtains mixture Mixed processes after do not have pulverizing process.This is because, when being provided with pulverizing process, being produced in composite graphite material sometimes The raw plane of fracture.

Constitute adhesive A, flaky graphite material B and the graphite material of composite graphite material of the invention (negative material) The proportion of C is essentially identical with the proportion of each composition of feed states.Therefore, constitute composite graphite material of the invention it is above-mentioned into Divide basically identical in terms of quality %, area %, volume % with each composition used with feed states.

In the present invention, adhesive A, the flakey as the raw material used when manufacturing composite graphite material of the invention are made The usage amount of graphite material B and graphite material C and the adhesive A, the flaky graphite material that constitute composite graphite material of the invention Expect that the content of B and graphite material C is substantially uniform.Additionally, making as the raw material used when manufacturing composite graphite material of the invention Flaky graphite material B and the shape of graphite material C maintenance is substantially obtained in composite graphite material of the invention.

The manufacture method to composite graphite material of the invention is illustrated below.

The manufacture method of composite graphite material of the invention has following operation：Will be by carbon material and/or low-crystalline stone Ink material formed adhesive A or described adhesive A precursor,

Flaky graphite material B and

The graphite material C mixing of spheroidizing or approximate sphericity, the mixed processes for obtaining mixture, and

The mixture obtained in mixed processes is heat-treated at 700~3300 DEG C, is obtained of the invention The heat treatment step of composite graphite material.

Mixed processes are illustrated below.

Mixed processes are the adhesive A or described adhesive A that will be formed by carbon material and/or low-crystalline graphite material The graphite material C mixing of precursor, flaky graphite material B and spheroidizing or approximate sphericity, the operation for obtaining mixture.

Carbon material, low-crystalline graphite material, the bonding used in the manufacture method of composite graphite material of the invention The graphite material C of agent A, flaky graphite material B, spheroidizing or approximate sphericity and composition composite graphite material of the invention Each composition is identical.

As the precursor of adhesive A, for example, can be that the precursor for making adhesive A is in the material of molten condition or will bond The material of the precursor dispersion of agent A or the state being dissolved in decentralized medium.

As decentralized medium, as long as can dissolve and/or dispersing binder A, its species is not restricted, for example can be with It is oil, creasote, 1-METHYLPYRROLIDONE, dimethylformamide, water, alcohol, toluene etc. in tar.

From can obtain initial charge/discharge efficiency higher and then more excellent fast charging and discharging characteristic and excellent can be obtained From the point of view of different cycle characteristics, relative to the mass parts of adhesive A 100, the amount of decentralized medium is preferably 5~1000 mass Part, more preferably 50~400 mass parts.

The amount of adhesive A can be being closed by adjusting the amount (adhesive A is total with decentralized medium) of the precursor of adhesive A In the range of reason.From can obtain initial charge/discharge efficiency higher and then more excellent fast charging and discharging characteristic can be obtained From the point of view of excellent cycle characteristics, total 100 mass parts relative to flaky graphite material B and graphite material C are glued The amount of the precursor of mixture A is preferably 0.01~150 mass parts, more preferably 0.2~20 mass parts.

The removing of the decentralized medium can be carried out before above-mentioned heat treatment or in heat treatment.And then, using advance graphite The flaky graphite material of change as flaky graphite material B precursor when, can more than 700 DEG C, less than 1500 DEG C at enter The above-mentioned heat treatment of row.

In mixed processes, to the mixed method for mentioned component to be formed mixture without specifically limited.For example can be with Carried out using biaxial kneader etc..

Mixing can more than 20 DEG C, less than 700 DEG C under conditions of carry out.

To the order of addition of composition without specifically limited.For example can be above-mentioned (1)~(4).

Heat treatment step is illustrated below.

Heat treatment step be the mixture obtained in above-mentioned mixed processes is heat-treated at 700~3300 DEG C, Obtain the operation of composite graphite material of the invention.

In heat treatment step, can be by the mixture to being obtained in mixed processes as described above 700~3300 It is heat-treated at DEG C and is obtained composite graphite material of the invention.

From the initial charge/discharge efficiency that can obtain discharge capacity higher and Geng Gao and then can obtain more excellent fast From the point of view of fast charge-discharge characteristic and excellent cycle characteristics, temperature is preferably 800~2200 DEG C, more preferably 900~ 1500℃。

In heat treatment step, heat treatment can be carried out repeatedly by changing temperature.Additionally, when being repeatedly heat-treated, At least 1 time heat treatment therein can be made for 700~3300 DEG C and make at least 1 time heat treatment less than 700 DEG C.To its sequentially without It is specifically limited.

In heat treatment step, can make to be heat-treated after being pre-formed vacuum in processing system, also can be under vacuum conditions It is heat-treated.

The manufacture method of composite graphite material of the invention can between mixed processes and heat treatment step also have to The mixture obtained in mixed processes carries out the mechanochemistry treatment process of mechanochemistry treatment.In this case, can obtain more Discharge capacity high and the initial charge/discharge efficiency of Geng Gao, and then more excellent fast charging and discharging characteristic can be obtained and excellent followed Ring property.

Mechanochemistry operation is illustrated below.

Mechanochemistry operation is the operation that mixture to being obtained in mixed processes carries out mechanochemistry treatment.

Mechanochemistry treatment is the place that mixture to being obtained in mixed processes applies compression stress and/or shearing force repeatedly Reason.Processed by mechanochemistry, be attached on graphite material C with can expeditiously making flaky graphite material B overshooting shapes.

To compression stress, the size of shearing force without specifically limited.Its size can be made to be that will not make the flakey in mixture Graphite material B and/or graphite material C is broken by bad degree.

As the device that mechanochemistry is processed, for example, can be that " Mechano-micro system " (nara machinery makes It is manufactured), extruder, ball mill, planetary ball mill, " Mechano-fusion system " (thin close Krona company system in river Make), " Nobilta " (thin river close Krona company manufacture), " Hybridization " (nara machinery makes manufactured), screw Grinding machine etc. compresses shearing processing unit (plant).

In the case where the manufacture method of composite graphite material of the invention also has mechanochemistry treatment process, can pass through The mechanochemistry processed material of the gained in mechanochemistry treatment process is carried out in heat treatment step, at 700~3300 DEG C It is heat-treated to manufacture composite graphite material of the invention.

Heat treatment step is same as described above.

In the case where the manufacture method of composite graphite material of the invention has above-mentioned (3), specifically, from can obtain To discharge capacity and Geng Gao higher initial charge/discharge efficiency so that more excellent fast charging and discharging characteristic and excellent can be obtained From the point of view of different cycle characteristics, method is preferably as follows：In mixed processes, will be by carbon material and/or low-crystalline graphite Adhesive A that material is formed or the precursor of adhesive A, the precursor of flaky graphite material B, flaky graphite is processed Spherical or approximate sphericity graphite material C and as needed using decentralized medium mix, manufacture dispersion (mixture), so Afterwards in heat treatment step, the dispersion to obtaining as described above is heat-treated at 700~3300 DEG C.Heat treatment can change Temperature is carried out repeatedly.

Additionally, when being repeatedly heat-treated, at least 1 time heat treatment therein can be made to be 700~3300 DEG C and at least 1 heat treatment is less than 700 DEG C.To it sequentially without specifically limited.

As the adhesive A used when composite graphite material of the invention is manufactured, it is possible to use the precursor of adhesive A. Can adhesive A is in the material of molten condition or is dispersed or dissolved in point adhesive A as the precursor of adhesive A The material of the state in dispersion media.

Decentralized medium is same as described above.

The removing of the decentralized medium can be carried out before the heat treatment or in heat treatment.And then, using advance graphite The flaky graphite material of change as flaky graphite material B precursor when, can more than 700 DEG C, less than 1500 DEG C at enter The row heat treatment.

Additionally, can be following system in the case where the manufacture method of composite graphite material of the invention has above-mentioned (4) Make method：In mixed processes, the precursor preparation property ground of flaky graphite material B is made mechanical external force is applied to graphite material C After attachment, the precursor of described adhesive A and the decentralized medium for using as needed are mixed, manufacture dispersion (mixture), so Afterwards in heat treatment step, the dispersion to obtaining as described above is heat-treated at 700~3300 DEG C.Heat treatment can change Temperature is carried out repeatedly.Additionally, when being repeatedly heat-treated, at least 1 time heat treatment therein can be made to be 700~3300 DEG C and at least 1 time heat treatment be less than 700 DEG C.To it sequentially without specifically limited.For applying mechanical external force, it is possible to use with Identical method under the manufacture method of above-mentioned graphite material C.It is preferred that before making flaky graphite material B by applying mechanical external force A part for body is embedded, attachment (attachment of preparation property ground) is on the surface of the graphite material C.This is because, outer by machinery The applying of power and the effect of the side of adhesive A two, the adhesive force of flaky graphite material B and graphite material C are uprised, and then, scale Dispersiveness raisings of the shape graphite material B in composite graphite material (negative material), can fully manifest flaky graphite material B Effect.

(lithium ion secondary battery cathode)

The making of lithium ion secondary battery cathode (being only designated as negative pole sometimes below) of the invention can be according to common negative The preparation method of pole is carried out, as long as the preparation method that the negative pole of stabilization in chemistry, electrochemistry can be obtained, without special limit System.The composite graphite material used in negative pole of the invention is composite graphite material of the invention, without specifically limited.

Can be used in the making of negative pole to the negative pole that adhesive is added in above-mentioned composite graphite material (negative material) Mixture.As adhesive, the material to electrolyte with chemical stability, electrochemical stability is preferably used, for example, can made With the fluororesin such as polyvinylidene fluoride, polytetrafluoroethylene (PTFE), polyethylene, polyvinyl alcohol, also styrene butadiene ribber, carboxymethyl Cellulose etc..These adhesives can be used together.1~20 mass % that adhesive is generally preferably accounted in cathode agent total amount.

1-METHYLPYRROLIDONE, the diformazan of the common solvents as negative pole making can be used in the making of negative pole Base formamide, water, alcohol etc..

Negative pole for example can by cathode agent is disperseed in a solvent, after the cathode agent that is modulated into pasty state, by this Cathode agent is applied in the one or two sides of collector, dries and make.In such manner, it is possible to obtain anode mixture layer (active matter Matter) it is uniform and be firmly bonded to the negative pole on collector.

More specifically, for example by the particle of above-mentioned composite graphite material (negative material), fluororesin powder or styrene Water dispersant and the solvent mixing of butadiene rubber, form slurry after, using known mixer, mixer, kneading machine, pinch Conjunction machine etc. is stirred mixing, modulation cathode agent paste.Cathode agent paste is applied on collector and dried, anode mixture layer It is just uniform and be firmly bonded on collector.The thickness of anode mixture layer is 10~200 μm, more preferably 30~100 μm.

Additionally, anode mixture layer can also be by by the particle of above-mentioned composite graphite material (negative material) and polyethylene, poly- It is the toner such as vinyl alcohol dry type mixing, hot-forming in metal die and make.But, it is terrible in dry type mixing To sufficient negative pole intensity, it is necessary to using substantial amounts of binding agent, when binding agent is excessive, discharge capacity, fast charging and discharging efficiency have When can reduce.

The pressure viscosity such as forcing press pressurization are carried out after formation anode mixture layer, anode mixture layer and collector can be further improved Bonding strength.

From from the point of view of the volume capacity for improving negative pole, the density of anode mixture layer is preferably in 1.70g/cm³More than, especially It is preferably in 1.75g/cm³More than.

To the shape of collector that is used in negative pole without specifically limited, the preferably mesh such as foil-like, sieve-like, woven wire Deng.As the material of collector, preferably copper, stainless steel, nickel etc..When for foil-like, the thickness of collector is preferably 5~20 μ m。

(lithium rechargeable battery)

Lithium rechargeable battery (secondary cell of the invention) of the invention is formed using above-mentioned negative pole.Above-mentioned negative pole is used Composite graphite material of the invention is formed.

Secondary cell of the invention is except using without specifically limited, other battery inscapes are according to logical in addition to above-mentioned negative pole The key element of normal secondary cell.That is, it is major cell inscape with electrolyte, negative pole and positive pole, these key elements are for example sealed Enter in battery case.And, negative pole and positive pole play the carrier of lithium ion respectively, and lithium ion is from negative pole deintercalation during charging.

(positive pole)

The positive pole used in secondary cell of the invention by positive electrode, binding agent and conductive material for example by that will be formed Anode mixture be applied to the surface of collector and formed.As positive electrode (positive active material), it is possible to use lithiumation is closed Thing, but it is preferably able to the material of an adequate amount of lithium of insertion/deintercalation.It is, for example possible to use lithium-containing transition metal oxide, transition gold Category chalcogenide, barium oxide, other lithium compounds, chemical formula M_xMo₆OS_8-Y(in formula, X is the numerical value of 0≤X≤4 scope, Y The numerical value of 0≤Y≤1 scope, M is at least one transition metal) represent Xue Fulie phases (Chevrel phases) compound, Activated carbon, NACF etc..Above-mentioned barium oxide is V₂O₅、V₆O₁₃、V₂O₄、V₃O₈Deng.

Above-mentioned lithium-containing transition metal oxide is the composite oxides of lithium and transition metal, can be that solid solution has lithium and 2 kinds The material of above transition metal.Composite oxides can be used alone, but also two or more is applied in combination.Lithium-containing transition metal is aoxidized Thing specifically can use LiM¹ _1-XM² _XO₂(in formula, X is the numerical value of 0≤X≤1 scope, M¹、M²It is at least one transition metal) or LiM¹ _1-YM² _YO₄(in formula, Y is the numerical value of 0≤Y≤1 scope, M¹、M²It is at least one transition metal) represent.

M¹、M²Represented transition metal is Co, Ni, Mn, Cr, Ti, V, Fe, Zn, Al, In, Sn etc., preferably Co, Mn, Cr, Ti, V, Fe, Al etc..Preferred specific example is LiCoO₂、LiNiO₂、LiMnO₂、LiNi_0.9Co_0.1O₂、LiNi_0.5Co_0.5O₂Deng.

Lithium-containing transition metal oxide for example can be by with lithium, the oxide of transition metal, hydroxide, salt etc. Beginning raw material, these initiation materials is mixed according to the composition of desired metal oxide, under oxygen atmosphere, 600~1000 It is calcined at a temperature of DEG C and is obtained.

Positive active material can be used alone above-mentioned lithium compound, but also two or more is used in combination.Additionally, can add in positive pole Plus the alkali carbonate such as lithium carbonate.

Positive pole can for example be formed by by above-mentioned lithium compound, binding agent and imparting positive pole with the conductive material of electric conductivity Anode mixture be applied in the one or two sides of collector, form positive electrode material mixture layer and make.As binding agent, it is possible to use With the binding agent identical material used in the making of negative pole.As conductive material, it is possible to use the carbon material such as graphite, carbon black.

Positive pole as negative pole, can by by anode mixture disperse in a solvent, the anode mixture that is tuned into pasty state is coated on On collector and dry and form positive electrode material mixture layer, also can further carry out forcing press pressurization etc. after positive electrode material mixture layer is formed Pressure viscosity.So, positive electrode material mixture layer is just by uniform and be firmly bonded on collector.

To the shape of collector without specifically limited, preferably mesh such as foil-like, sieve-like, woven wire, etc..Collector Material for aluminium, stainless steel, nickel etc..When for foil-like, the thickness of collector is advisable with 10~40 μm.

(nonaqueous electrolyte)

The nonaqueous electrolyte (electrolyte) used in secondary cell of the invention is used in common nonaqueous electrolytic solution Electrolytic salt.As dielectric salt, for example, can use LiPF₆、LiBF₄、LiAsF₆、LiClO₄、LiB(C₆H₅)₄、LiCl、 LiBr、LiCF₃SO₃、LiCH₃SO₃、LiN(CF₃SO₂)₂、LiC(CF₃SO₂)₃、LiN(CF₃CH₂OSO₂)₂、LiN(CF₃CF₂OSO₂)₂、 LiN(HCF₂CF₂CH₂OSO₂)₂、LiN〔(CF₃)₂CHOSO₂〕₂、LiB〔C₆H₃(CF₃)₂〕₄、LiAlCl₄、LiSiF₅Deng lithium salts.From oxygen From the point of view of change stability, particularly preferred LiPF₆、LiBF₄。

The electrolytic salinity of electrolyte is preferably 0.1~5mol/L, more preferably 0.5~3mol/L.

Nonaqueous electrolyte can be liquid, can also be the polyelectrolyte of solid, gel etc..When for the former when, Nonaqueous electrolyte battery constitutes so-called lithium rechargeable battery, and when for the latter, respectively constitutes polymer solid electrolyte The polymer electrolyte cells such as battery, polymer gel electrolyte battery.

As the solvent for constituting nonaqueous electrolyte, it is possible to use ethylene carbonate, propene carbonate, dimethyl carbonate, carbon The carbonic esters such as diethyl phthalate, 1,1- or 1,2- dimethoxy-ethane, 1,2- diethoxyethane, tetrahydrofuran, 2- methyl The ethers, ring fourth such as tetrahydrofuran, gamma-butyrolacton, DOX, 4- methyl isophthalic acids, 3- dioxolanes, methyl phenyl ethers anisole, ether The nitriles, trimethylborate, quanmethyl silicate, nitromethane, diformazan such as the thioethers such as sulfone, methyl sulfolane, acetonitrile, chloro nitrile, propionitrile Base formamide, 1-METHYLPYRROLIDONE, ethyl acetate, trimethyl orthoformate, nitrobenzene, chlorobenzoyl chloride, benzoyl bromide, tetrahydrochysene Non-proton organic solvents such as thiophene, dimethyl sulfoxide, 3- methyl -2- oxazolidones, ethylene glycol, dimethyl sulfite etc..

In the case of using above-mentioned polyelectrolyte, preferably use with the height of plasticizer (nonaqueous electrolytic solution) gelation Molecular compound is used as matrix.As the macromolecular compound for constituting the matrix, polyethylene glycol oxide can be used alone or as a mixture Or ethers macromolecular compound, polymethacrylates system macromolecular compound, the polyacrylate system macromolecule such as its crosslinked Fluorine system macromolecular compound such as compound, polyvinylidene fluoride or vinylidene difluoride-hexafluoropropylene copolymer etc..Particularly preferably make With the fluorine system macromolecular compound such as polyvinylidene fluoride or vinylidene difluoride-hexafluoropropylene copolymer.

Plasticizer can be added in above-mentioned polymer solid electrolyte or polymer gel electrolyte, as plasticizer, Above-mentioned electrolytic salt, nonaqueous solvents can be used.When for polymer gel electrolyte, as in the nonaqueous electrolytic solution of plasticizer Electrolytic salinity be preferably 0.1~5mol/L, more preferably 0.5~2mol/L.

To the preparation method of above-mentioned polymer solid electrolyte without specifically limited, for example, it can be following method etc.：Mixing Macromolecular compound, lithium salts and the nonaqueous solvents (plasticizer) of matrix are constituted, the method for heating, melting macromolecule；By height Molecular compound, lithium salts and nonaqueous solvents (plasticizer) evaporate mixing organic solvent afterwards in being dissolved into mixing organic solvent Method；Mixed polymerization monomer, lithium salts and nonaqueous solvents (plasticizer), to mixture irradiation ultraviolet radiation, electron ray, molecule Ray etc. makes the method that polymerizable monomer is polymerized, obtains macromolecular compound.

The ratio of the nonaqueous solvents (plasticizer) in polymer solid electrolyte is preferably 10~90 mass %, more preferably 30~80 mass %.During less than 10 mass %, conductance reduction, during more than 90 mass %, mechanical strength weakens, and is difficult masking.

Barrier film can also be used in lithium rechargeable battery of the invention.

To the material of barrier film without specifically limited, for example can be weave cotton cloth, non-woven fabrics, synthetic resin micro-porous film etc..To close Resin micro-porous film is preferred, wherein, from from the aspect of thickness, film-strength, membrane resistance, it is preferred with polyolefin micro-porous film. Specifically, it is polyethylene and polypropylene micro-porous film or micro-porous film that they are combined into.

Secondary cell of the invention by by above-mentioned negative pole, positive pole and nonaqueous electrolyte for example press negative pole, nonaqueous electrolyte, The order of positive pole is laminated and is received into the exterior material of battery and makes.

Nonaqueous electrolyte can also be configured in the outside of negative pole and positive pole.

To the structure of secondary cell of the invention without specifically limited, to its shape, form also without specifically limited, can according to On the way, loading device, required charge/discharge capacity etc. are arbitrarily selected from cylinder type, square, Coin shape, coin shape etc..In order to Security hermetic type battery with nonaqueous electrolyte higher is obtained, preferably with battery can be perceived under the abnormal conditions such as overcharge Internal pressure rises and cuts off the means of electric current.

In the case of for polymer electrolyte cells, it is also possible to form the structure being sealing into laminated film.

Embodiment

More specific description is carried out to the present invention below by embodiment, but the invention is not limited in these embodiments. Additionally, in following examples and comparative example, make structure as shown in Figure 2 evaluation is with coin shape secondary cell and is commented Valency.Actual battery can purpose of the invention, make according to known methods.

(embodiment 1)

(modulation of adhesive A)

The mass parts of tar asphalt 50 are dissolved into tar in oily 50 mass parts, the precursor solution of adhesive A is obtained.

(modulation of flaky graphite material B)

Native graphite is crushed in the case where being modulated, the average grain diameter for making gained flaky graphite material B is 4 μm, Mean aspect ratio is 35.The d002 of gained flaky graphite material B is 0.3357nm.

(modulation of graphite material C)

While by flake natural graphite (20 μm of average grain diameter), with counter-jet mill, (the thin close Krona company in river manufactures；Model Mechanical external force 200AFG) is applied to it on 1 hour side of machine interior circulation under air pressure 300kPa, spherical granulation natural stone is obtained Ink.Then, granulation incomplete micro mist of the particle diameter below 5 μm is removed.Meal is removed again, makes to form the lower particle of 75 μm of sieves.With The section of SEM observation gained granulation native graphite, as a result finds, flake natural graphite is arranged with concentric circles Row.Average grain diameter is 18 μm, and length-width ratio is that 1.4, d002 is 0.3356.

(modulation of composite graphite material (negative material))

By the mass parts of precursor solution 50 of above-mentioned adhesive A, the matter of precursor 1 of above-mentioned flake natural graphite comminution of material B Amount part and the above-mentioned mass parts of granulated graphite material C 95.5 twin axle heat kneader and 1 hour (mixing work are kneaded at 150 DEG C Sequence), the quality proportion of composing for making the gained mass parts of composite graphite material 100 is：The bonding formed by low-crystalline graphite material Agent A (carbon material from coal tar asphalt)：Flaky graphite material B (flake natural graphite comminution of material)：Granulated graphite Material C (granulation the native graphite)=︰ 95.5 of 3.5 ︰ 1.Then, it is evacuated, removes the decentralized medium in the mixture (in tar Oil).After gained mixture is calcined 10 hours at 550 DEG C, heat treatment (heat treatment step) in 3 hours is implemented at 1250 DEG C. Shape is substantially identical with granulation native graphite, and average grain diameter is 18 μm.Flake natural graphite comminution of material is via from coal tar The carbon material of oil asphalt is partly attached on granulation native graphite with overshooting shape, on the other hand, be there is also and is not attached to make Part on grain native graphite, by the part, the contact with adjacent particle easily increases.Shape observation SEM (scanning electrons Microscope) carry out.The SEM photograph of gained composite graphite material outward appearance is shown in Fig. 3 (3000 times of multiplying power).

In figure 3, composite graphite material 30 has flaky graphite material B34,36, graphite material C32 and from coal tar The carbon material of oil asphalt.It is attached on graphite material C32 flaky graphite material B34,36 overshooting shapes.Additionally, there is also not The flaky graphite material B38 on graphite material C32 is attached to, by the part, (is not shown in figure with adjacent graphite material C Go out) contact easily increase.

Additionally, the crystallinity on the carbon material from coal tar asphalt as adhesive A, only to as the carbon material The coal tar asphalt of precursor is heat-treated by thermal history similarly to Example 1, and is determined with above-mentioned X-ray diffraction method Its lattice plane is spaced d002.Result finds, compared with the granulated graphite material C of composite graphite material of embodiment 1 is constituted, the crystalline substance D002 is big at lattice face interval, is 0.3365nm, is less than as the crystallinity of the carbon material from coal tar asphalt of adhesive A and constituted The crystallinity of the graphite material C of the composite graphite material of embodiment 1.

(modulation of cathode agent)

By the mass parts of above-mentioned composite graphite material 98, the mass parts of adhesive carboxymethylcellulose calcium 1 and styrene butadiene rubber The mass parts of glue 1 are added to the water, stirring, modulate cathode agent paste.

(making of working electrode)

Above-mentioned cathode agent paste is applied on thick 16 μm of Copper Foil with uniform thickness, and then is made with 90 DEG C in a vacuum Decentralized medium water evaporation is simultaneously dried.Then, cathode agent on Copper Foil is coated on 12kN/cm to this with handpress² (120MPa) pressurizes, and is further punched into the toroidal of diameter 15.5mm, is thus obtained and is closed with the negative pole closely sealed with Copper Foil The working electrode of oxidant layer (thick 60 μm).The density of anode mixture layer is 1.75g/cm³.Working electrode without extend, deformation, from section Without depression on the collector seen.

(making to electrode)

Lithium metal foil is pressed on nickel screen, the toroidal of diameter 15.5mm is punched into, the collector formed by nickel screen is made With closely sealed lithium metal foil (thickness 0.5mm) composition on the collector to electrode (positive pole).

(electrolyte, barrier film)

By LiPF₆It is dissolved in the mixed solvent of the volume % of 33 volume %- methyl ethyl carbonates of ethylene carbonate 67, makes concentration It is 1mol/L, prepares nonaqueous electrolytic solution.Make gained nonaqueous electrolytic solution infiltration polypropylene porous body (thick 20 μm), be obtained soaked with electricity Solve the barrier film of liquid.

(making of evaluation electricity pool)

The coin shape secondary cell shown in Fig. 2 is made as evaluation battery.Fig. 2 is shown in charge and discharge electric test in embodiment Coin shape evaluates the schematic section of the structure of battery.In fig. 2, in the expression of symbol 8 embodiment in charge and discharge electric test The coin shape for using evaluates battery.The structure of battery 8 is as follows：Exterior cap 1 and outer tinning 3 pass through insulating washer 6 in its periphery Rivet and closed two periphery, inside battery be sequentially laminated with from the inner surface of outer tinning 3 formed by nickel screen collector 7a, Lithium paper tinsel formed it is cylindric to electrode (positive pole) 4, the barrier film 5 soaked with electrolyte, by cathode agent formed it is discoid Working electrode (negative pole) 2 and the collector 7b formed by Copper Foil.

Battery 8 is obtained by the following method：To be sandwiched soaked with the barrier film 5 of electrolyte and be layered in closely sealed in collector 7b On working electrode (negative pole) 2 with it is closely sealed on collector 7a between electrode (positive pole) 4, it is then, working electrode is (negative Pole) 2 it is received into exterior cap 1, electrode (positive pole) 4 will be received into outer tinning 3, exterior cap 1 is closed one with outer tinning 3 Rise, insulating washer 6 is further inserted in exterior cap 1 and the periphery of outer tinning 3, rivet and closed two periphery.

In actual battery, battery 8 is (negative by the working electrode containing the graphite particle that can be used as negative electrode active material Pole) 2 and being constituted to electrode (positive pole) 4 of being formed by lithium metal foil.

Above-mentioned battery of evaluating obtained like that is carried out into following charge and discharge electric tests at a temperature of 25 DEG C, to unit mass Discharge capacity, initial charge/discharge efficiency, rapid charge rate, repid discharge rate and cycle characteristics are evaluated.Evaluation result is shown In Tables 1 and 2.

(discharge capacity of unit mass)

Charged with the constant current of 0.9mA, until loop voltage reaches 0mV, then, switched to constant-potential charge, Continue to charge until current value reaches 20 μ A.Thus the turn on angle between obtains the charging capacity of unit mass.Afterwards, 120 are stopped Minute.Then constant current electric discharge is carried out with the current value of 0.9mA, until loop voltage reaches 1.5V, thus between turn on angle Obtain the discharge capacity of unit mass.In this, as the 1st circulation.Following formula is passed through by the charging capacity and discharge capacity of the 1st circulation Calculate initial charge/discharge efficiency.

Initial charge/discharge efficiency (%)=(discharge capacity/charging capacity) × 100

In addition, in this experiment, lithium ion is inhaled the process being embedded into composite graphite material and be referred to as charging, will be from composite stone The process of deintercalation is referred to as electric discharge in ink material.

(rapid charge rate)

Then the 1st circulation, quick charge is carried out in the 2nd circulation.

5 times i.e. 4.5mA for making current value be the 1st circulation, carries out constant current charge, until loop voltage reaches 0mV, asks Go out constant current charge capacity, rapid charge rate is calculated by following formula.

Rapid charge rate (%)=(discharge capacity of the circulation of constant current charge capacity/1st of the 2nd circulation) × 100

(repid discharge rate)

Battery is evaluated using other, then the 1st circulation, repid discharge is carried out in the 2nd circulation.As described above, carrying out After 1st circulation, charged in the same manner as the 1st circulation, 20 times, i.e. 18mA for then making current value be the 1st circulation is carried out constant Current discharge, until loop voltage reaches 1.5V.Thus the turn on angle between obtains the discharge capacity of unit mass, is calculated with following formula Repid discharge rate.

Repid discharge rate (%)=(discharge capacity of the circulation of discharge capacity/1st of the 2nd circulation) × 100

(cycle characteristics)

Make and different commented with the evaluation battery of the evaluation discharge capacity of unit mass, rapid charge rate, repid discharge rate Valency battery, carries out following evaluation.

The constant current charge of 4.0mA is carried out, until loop voltage reaches 0mV, constant-potential charge is then switched to, after It is continuous to charge up to current value reaches 20 μ A, afterwards, stop 120 minutes.Then constant current is carried out with the current value of 4.0mA to put Electricity, until loop voltage reaches 1.5mV.Discharge and recharge is repeated 20 times, is calculated with following formula by the discharge capacity of gained unit mass Cycle characteristics.

Cycle characteristics (%)=(discharge capacity of the circulation of discharge capacity/1st of the 20th circulation) × 100

(embodiment 2)

Except the ratio for making flaky graphite material B in embodiment 1 is that 10 mass parts, the ratio of graphite material C are Beyond 86.5 mass parts, composite graphite material is modulated similarly to Example 1, negative pole and evaluation are made similarly to Example 1 Battery, and evaluation test is carried out similarly to Example 1.The evaluation result of battery behavior is shown in Tables 1 and 2.

(embodiment 3)

Except the ratio for making flaky graphite material B in embodiment 1 is that 25 mass parts, the ratio of graphite material C are Beyond 71.5 mass parts, composite graphite material is modulated similarly to Example 1, negative pole and evaluation are made similarly to Example 1 Battery, and evaluation test is carried out similarly to Example 1.The evaluation result of battery behavior is shown in Tables 1 and 2.

As shown in Table 1 and Table 2, the evaluation electricity consumption obtained by the composite graphite material of embodiment 1~3 is used in working electrode Pond shows high discharge capacity, and with initial charge/discharge efficiency high.Also show excellent fast charging and discharging efficiency and excellent Different cycle characteristics.

(embodiment 4)

In addition to making adhesive A for coal tar in embodiment 1, decentralized medium is not used, adjust similarly to Example 1 Composite graphite material processed, makes negative pole and evaluates battery, and carry out evaluation examination similarly to Example 1 similarly to Example 1 Test.The evaluation result of battery behavior is shown in Tables 1 and 2.

Additionally, crystallinity for the carbon material from coal tar as adhesive A, only to as the carbon material precursor Coal tar be heat-treated by thermal history same as Example 1, between determining its lattice plane with above-mentioned X-ray diffraction method Every d002.Result finds, compared with the granulated graphite material C of composite graphite material of embodiment 1 is constituted, lattice plane interval D002 is big, is 0.3456nm, is less than as the crystallinity of the carbon material from coal tar asphalt of adhesive A and constitutes embodiment 1 Composite graphite material graphite material C crystallinity.

As shown in Table 1 and Table 2, the evaluation battery for being obtained as working electrode using the composite graphite material of embodiment 4 is shown High discharge capacity is shown and with initial charge/discharge efficiency high.Also show excellent fast charging and discharging efficiency and excellent follow Ring property.However, compared with the situation using decentralized medium, initial charge/discharge efficiency, fast charging and discharging characteristic, cycle characteristics It is low.

(comparative example 1)

In addition to not using flaky graphite material B in embodiment 1, composite graphite is modulated similarly to Example 1 Material, makes negative pole and evaluates battery, and carry out evaluation test similarly to Example 1 similarly to Example 1.Battery behavior Evaluation result be shown in Tables 1 and 2.

As shown in Table 1 and Table 2, on the graphite material C it is unattached have flaky graphite material B in the case of, it is impossible to obtain Fast charging and discharging efficiency high and cycle characteristics.This is probably because the interparticle electric conductivity of graphite material C is not enough, graphite The utilization rate reduction of material C.

(comparative example 2)

Except in embodiment 1 by flaky graphite material B change into fiber graphite material (gas-phase growth of carbon fibre, it is clear With the production of electrician company, VGCF, diameter 150nm, length-width ratio 50), composite graphite material is modulated similarly to Example 1, with reality Apply example 1 similarly to make negative pole and evaluate battery, and evaluated similarly to Example 1.The evaluation result of battery behavior is shown In Tables 1 and 2.

As shown in Table 1 and Table 2, do not use flaky graphite and by fiber graphite composition of material in the case of, nothing Method obtains fast charging and discharging efficiency high.This is probably because when for fibrous material, graphite material C is prevented during pressurization Orientation effect it is insufficient and/or effect that prevent die mould electrode inaccessible is insufficient, it is impossible to substantially ensure that logical fluidity.

(embodiment 5)

Except the average grain diameter for making flaky graphite material B (flake natural graphite comminution of material) in embodiment 1 is 10 μm are in addition, and composite graphite material is modulated similarly to Example 1, and negative pole is made similarly to Example 1 and battery is evaluated, and Evaluation test is carried out similarly to Example 1.

(embodiment 6)

Except the average grain diameter for making flaky graphite material B (flake natural graphite comminution of material) in embodiment 1 is 15 μm are in addition, and composite graphite material is modulated similarly to Example 1, and negative pole is made similarly to Example 1 and battery is evaluated, and Evaluation test is carried out similarly to Example 1.

(embodiment 7)

Except the squama for making flaky graphite material B (flake natural graphite comminution of material) be flexure type in embodiment 1 Piece (Tap density 0.2g/cm³) beyond, composite graphite material is modulated similarly to Example 1, make negative similarly to Example 1 Pole and evaluation battery, and evaluation test is carried out similarly to Example 1.The SEM photograph of gained composite graphite material outward appearance is shown In Fig. 4 (multiplying power is 3000 times).

In fig. 4, composite graphite material 40 has flaky graphite material B44, graphite material C42 and from coal tar drip Blue or green carbon material.Flaky graphite material B44 bends to L fonts, thus, it is possible to say the overshooting shapes of flaky graphite material B 44 ground It is attached on graphite material C42.

(comparative example 3)

Except the ratio for making flaky graphite material B (flake natural graphite comminution of material) in embodiment 1 is 40 matter Amount part, graphite material C are beyond 56.5 mass parts, composite graphite material to be modulated similarly to Example 1, similarly to Example 1 Ground makes negative pole and evaluates battery, and carries out evaluation test similarly to Example 1.The evaluation result of battery behavior is shown in table 1 With table 2.

As shown in Table 1 and Table 2, in the presence of flaky graphite material B is with 40 mass parts, it is impossible to obtain fast charging and discharging high Efficiency, cycle characteristics.This is probably because the flaky graphite material B being present in excess is orientated in battery and/or prevents die mould The inaccessible effect of electrode is insufficient, it is impossible to substantially ensure that logical fluidity.

(comparative example 4)

Obtained composite graphite material will be crushed with airslide disintegrating mill in embodiment 1, and make average grain diameter be 15 μm.With reality Apply example 1 similarly to make negative pole and evaluate battery, and carry out evaluation test similarly to Example 1.The evaluation knot of battery behavior Fruit is shown in Tables 1 and 2.

As shown in Table 1 and Table 2, in the case where crushing is implemented, the improvement effect of initial charge/discharge efficiency and cycle characteristics It is really insufficient.This be probably because, due to crush, reactivity face (plane of disruption) exposes, with electrolyte contacts and produce reaction, Product forms resistance.And be probably because and/or being attached to flaky graphite material B on graphite material C Surface because crushing And come off, it is impossible to obtain sufficient cycle characteristics improved effect.

(embodiment 8)

By mixing (mixed processes), the quality proportion of composing for making the gained mass parts of composite graphite material 100 is adhesive A (carbon material) ︰ flaky graphite materials B (the flake natural graphite comminution of material) ︰ granulated graphite materials from coal tar asphalt C (granulation the native graphite)=︰ 95.5 of 3.5 ︰ 1, using can repeatedly to mixture apply compression stress, shearing force device carry out machine Tool is chemically treated (mechanochemistry treatment process).Calcination process (heat is carried out to gained compound in nitrogen stream, at 1250 DEG C Treatment process), modulate composite graphite particle.Shape is substantially identical with granulation native graphite, and average grain diameter is 18 μm.

Using resulting materials as composite graphite material, negative pole is made similarly to Example 1 and battery is evaluated, and with implementation Example 1 similarly carries out evaluation test.The evaluation result of battery behavior is shown in Tables 1 and 2.

Additionally, for the crystallinity of the carbon material from coal tar asphalt as adhesive A, only to as the carbon material The coal tar asphalt of precursor is heat-treated by hot Cheng Li same as Example 1, and it is determined with above-mentioned X-ray diffraction method Lattice plane is spaced d002.Result finds, compared with the granulated graphite material C of composite graphite material of embodiment 1 is constituted, the lattice D002 is big at face interval, is 0.3365nm, and crystallinity is low.

As shown in Table 1 and Table 2, the evaluation battery for being obtained as working electrode using the composite graphite material of embodiment 8 is shown High discharge capacity is shown and with initial charge/discharge efficiency high.Also show excellent fast charging and discharging efficiency and excellent follow Ring property.

(comparative example 5)

In addition to not using adhesive A in embodiment 8, composite graphite material is modulated similarly to Example 8, with reality Apply example 8 similarly to make negative pole and evaluate battery, and carry out evaluation test similarly to Example 8.The evaluation knot of battery behavior Fruit is shown in Tables 1 and 2.

As shown in Table 1 and Table 2, do not use adhesive A and physically by flaky graphite material B and graphite material C In the case of Composite, initial charge/discharge efficiency and fast charging and discharging, the improvement of cycle characteristics are insufficient.This be probably because For, because the reactivity of flaky graphite material B and/or graphite material C is showed out, reaction is produced with electrolyte contacts, Product forms resistance.It could also be because, because the attachment of flaky graphite material B is insufficient, cannot during repetition discharge and recharge The interparticle electric conductivity of adjoining is kept, the improvement of cycle characteristics is insufficient.

(comparative example 6)

In addition to adhesive A is 74 mass parts for 25 mass parts, graphite material C in embodiment 8, with embodiment 8 Composite graphite material is similarly modulated, negative pole is made similarly to Example 8 and battery is evaluated, and entered similarly to Example 8 Row evaluation test.The evaluation result of battery behavior is shown in Tables 1 and 2.

As shown in Table 1 and Table 2, when adhesive A is present in excess, discharge capacity, initial charge/discharge efficiency and quick charge, follow The improvement of ring property is insufficient.This is probably because the discharge capacity of adhesive A is few so that negative material is overall to be put Capacitance reduction.It could also be because, excessive adhesive A makes flaky graphite material B be embedded in graphite material C Surface On, it is impossible to it is sufficiently formed contact between adjacent particle.

With specified in the present invention composite graphite material make working electrode when, it is possible to increase anode mixture layer it is close Degree, discharge capacity, initial charge/discharge efficiency, rapid charge rate, repid discharge rate, cycle characteristics are excellent.On the other hand, with Not when present invention provide that interior composite graphite material makes working electrode, discharge capacity, initial charge/discharge efficiency, quick charge A certain (a little) item in rate, repid discharge rate, cycle characteristics is insufficient.

(comparative example 7)

The mass parts of precursor solution 15 of above-mentioned adhesive A, the mass parts of above-mentioned flake natural graphite 100 are added with twin axle Heat kneading machine is kneaded 1 hour at 150 DEG C, and relative to the mass parts of flake natural graphite 100, (coal tar is dripped to make adhesive A It is blue or green) it is 3.5 mass parts.Then, it is evacuated, removes the decentralized medium (oil in tar) in the mixture.By gained mixture After being calcined 10 hours at 550 DEG C, heat treatment (heat treatment step) in 5 hours is implemented at 1250 DEG C.Then airslide disintegrating mill is used Crush, modulate flakey coated graphite powder, make its average grain diameter be 35 for 4 μm, mean aspect ratio.

By mixing, make the mass parts of gained flakey coated graphite Fen ︰ graphite material C=4.5 Zhi Liang Fen ︰ 95.5, with institute Material is obtained as composite graphite material, negative pole is made similarly to Example 1 and battery is evaluated, and entered similarly to Example 1 Row evaluation test.The evaluation result of battery behavior is shown in Tables 1 and 2.

As shown in Table 1 and Table 2, in the case of simply mixing flakey coated graphite powder and graphite material C, initial stage charge and discharge The improvement of electrical efficiency and cycle characteristics is insufficient.This is probably because due to crushing, reactivity is showed out, with electrolysis Liquid is contacted and produces reaction, and product forms resistance.

(embodiment 9)

Except the quality proportion of composing for making the gained mass parts of composite graphite material 100 is to be formed by low-crystalline graphite material Adhesive A ︰ flaky graphite materials B (flake natural graphite comminution of material) ︰ granulated graphite material Cs：Small graphite particle Beyond the ︰ 1 of 1 ︰ of (Ketjen black, average grain diameter 40nm)=3.5 ︰ 94.5, composite graphite material is modulated similarly to Example 1, with reality Apply example 1 similarly to make negative pole and evaluate electrode, and carry out evaluation test similarly to Example 1.

The composite graphite material of the gained of embodiment 2~6,8,9 is as shown in figure 1, at least a portion of flaky graphite material B It is attached to via adhesive A overshooting shape on graphite material C.

Additionally, in embodiment 7, as shown in figure 4, flaky graphite material B44 bends, it can be said that flaky graphite It is attached on graphite material C42 material B44 overshooting shapes.

Table 2

In table 2, " kneading " in manufacture method column refers to have used twin axle to heat kneader in mixed processes." machine Tool " refers to that mechanochemistry treatment process has been carried out after mixed processes." mediate+crush " of comparative example 4 refers in mixed processes Middle use twin axle heating kneader is mixed, and gained composite graphite material is crushed." mixing " of comparative example 7 with than It is identical compared with example 4.

Composite graphite material of the invention can serve as being effectively facilitated miniaturization and the high performance of carrying equipment Lithium rechargeable battery negative material.

Symbol description：

1 exterior cap

2 working electrodes (negative pole)

3 outer tinnings

4 pairs of electrodes (positive pole)

5 barrier films

6 insulating washers

7a, 7b collector

8 batteries

10 composite graphite materials

12 adhesive As

14~18 flaky graphite material B

19 graphite material C

30 composite graphite materials

32 graphite material C

34th, 36,38 flaky graphite material B

40 composite graphite materials

42 graphite material C

44 flaky graphite material B

Claims

1. composite graphite material, its adhesive A, flaky graphite for being made up of carbon material and/or low-crystalline graphite material The graphite material C of material B and spheroidizing or approximate sphericity is constituted,

Wherein, at least a portion of the flaky graphite material B is attached to the graphite by described adhesive A overshooting shapes In material C,

Relative to described adhesive A, the flaky graphite material B, the graphite material C total amount, described adhesive A's contains Content for 0.1~20 mass %, the flaky graphite material B is measured in more than 0.05 mass %, less than 30 mass %, it is described The content of graphite material C is 99.8~50 mass %, and the composite graphite material does not have the plane of fracture,

The d002 of described adhesive A is 0.3358~0.3500nm,

The d002 of the flaky graphite material B in below 0.3380nm,

The d002 of the graphite material C is 0.3350~0.3380nm,

And d002s of the d002 of described adhesive A more than the graphite material C.

2. composite graphite material according to claim 1, it is characterised in that the average grain of the flaky graphite material B Footpath the graphite material C average grain diameter more than 1%, less than 80%.

3. composite graphite material according to claim 1 and 2, it is characterised in that by by the flaky graphite material Without pulverizing process after the mixed processing operation that the material B and/or graphite material C is processed with described adhesive A Manufacture method is manufactured.

4. composite graphite material according to claim 1 and 2, it is characterised in that for lithium ion secondary battery cathode.

5. composite graphite material according to claim 3, it is characterised in that for lithium ion secondary battery cathode.

6. anode material for lithium-ion secondary battery, it contains the composite graphite material any one of Claims 1 to 5.

7. lithium ion secondary battery negative pole, it contains the anode material for lithium-ion secondary battery described in claim 6.

8. lithium rechargeable battery, it has the lithium ion secondary battery negative pole described in claim 7.

9. the manufacture method of composite graphite material, it has：

The graphite material C of the precursor of adhesive A, flaky graphite material B and spheroidizing or approximate sphericity is mixed, is mixed The mixed processes of compound, the mixture to being obtained in the mixed processes is heat-treated at 700~3300 DEG C, is obtained institute At least a portion of flaky graphite material B is stated to be attached on the graphite material C by described adhesive A overshooting shapes, no The heat treatment step of the composite graphite material with the plane of fracture,

Described adhesive A is formed by the precursor of described adhesive A through the heat treatment, by carbon material and/or low-crystalline Graphite material is constituted,

Relative to described adhesive A, the flaky graphite material B, the graphite material C total amount, described adhesive A's contains Content for 0.1~20 mass %, the flaky graphite material B is measured in more than 0.05 mass %, less than 30 mass %, it is described The content of graphite material C is 99.8~50 mass %,

In below 0.3380nm, the d002 of the graphite material C is the d002 of the flaky graphite material B in mixed processes 0.3350~0.3380nm,

The d002 of the described adhesive A obtained after heat treatment is 0.3358~0.3500nm,

10. the manufacture method of composite graphite material according to claim 9, it is characterised in that the flaky graphite material Expect B average grain diameter the graphite material C average grain diameter more than 1%, less than 80%.

The manufacture method of 11. composite graphite material according to claim 9 or 10, it is characterised in that also with institute Stating the mixture obtained in mixed processes carries out the mechanochemistry treatment process of mechanochemistry treatment.